Composite Lug Wrapping Structure for Lightweight Load Transfer

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Solution Overview

Problem

Current composite materials face challenges in efficiently transferring loads in aerospace applications due to the limitations of metallic joints, which increase weight and cost, and existing fully composite designs often have weak structural performance and high manufacturing costs.

Innovation Solution

A composite part design featuring finite-length composite plies with specific fiber orientations and polymer matrices, wrapped in a counter-clockwise and clockwise direction around a component, providing additional transverse compression and minimizing the risk of local buckling through interleaved and additional composite wrapping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If metallic joints are used at rod ends for load transfer, then load transfer efficiency is improved, but overall weight increases and cost increases

Engineering Contradiction:
Improveload transfer efficiencyVSAvoidoverall weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The invention extracts and eliminates the metallic joint component from the composite structure, replacing it with a fully composite design that integrates the rod end directly into the composite material, thereby removing the source of weight increase while maintaining load transfer functionality through composite plies and wrapping

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention uses composite materials (fiber-reinforced polymers with wrapping plies) to replace metallic joints, achieving both weight reduction and maintained load transfer efficiency through the engineered composite structure with specific fiber orientations and wrapping configurations

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If holes are drilled and surrounding areas are machine in composite components to generate composite lugs, then metallic joint replacement is achieved, but structural performance becomes weak

Engineering Contradiction:
Improvejoint replacement feasibilityVSAvoidstructural performance
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The invention applies wrapping plies and reinforcement structures during the composite fabrication process itself, before final component completion, to pre-strengthen the rod end areas where loads will be transferred, preventing the structural weakness that would result from post-fabrication hole drilling and machining

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention applies different ply configurations and wrapping densities at specific locations (rod ends) versus other areas of the composite component, concentrating reinforcement where load transfer occurs while maintaining overall structural efficiency, rather than uniformly strengthening the entire component

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If advanced fully composite components are fabricated by complex fabrication methods such as braiding techniques, then metallic joints are eliminated, but manufacturing costs increase and design limitations arise

Engineering Contradiction:
Improvejoint elimination achievementVSAvoidfabrication method complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The invention segments the composite component into distinct regions (main body, rod ends, wrapping sections) that can be fabricated using standard, simplified methods, avoiding the need for complex integrated braiding techniques while still achieving full composite construction and joint elimination

Inventive Principle:
Principle #1Segmentation

4Ease of operation

If post-fabrication machining is performed on fully composite components, then assembly flexibility is improved, but risks of polymer damage increase

Engineering Contradiction:
Improveassembly flexibilityVSAvoidpolymer damage risk
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The invention performs all necessary machining operations (hole drilling, slot cutting, feature creation) during the composite fabrication process itself, before the material is cured and hardened, allowing easy modification without risking damage to the cured polymer matrix that would occur with post-fabrication machining

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3730280B1Composite lug with enhanced performance
Publication Date: 2023.04.19 HAMILTON SUNDSTRAND CORP
  • EP3730280B1 patent drawingFigure 1A~1E
  • EP3730280B1 patent drawingFigure 2~3
  • EP3730280B1 patent drawingFigure 4~5

AI summary

A composite part is provided and includes a component, a first set of first composite plies (111) with finite lengths and a second set of second composite plies (121) with finite lengths. A respective end of each of the first composite plies (111) is wrapped around the component in a clockwise wrapping direction and includes first fibers. A respective end of each of the second composite plies (121) is wrapped around the component in a counter-clockwise wrapping direction and includes second fibers.